JTB ⇝

jump trace buffer

(JTB) A feature of some pipelined processors (e.g. Amulet, Pentium?) which stores the source and destination addresses of the last few branch instuctions executed. When a branch instruction is fetched, its source is looked for in the JTB. If found, the next instuction fetch will be from the previous destination of that branch. If it turns out that the branch shouldn't have been taken this time, then the pipeline is flushed. This means that in a tight loop it is not necessary to flush the pipeline every time you jump back to the start.